Distinct Functional Network Connectivity for Abstract and Concrete Mental Imagery

Area of Science:

• Cognitive Neuroscience
• Psycholinguistics
• Neuroimaging

Background:

• Behavioral studies demonstrate concrete words are processed more efficiently than abstract words (concreteness effect).
• Previous fMRI studies compared neural activation patterns for concrete versus abstract concepts.
• The current study investigates differences in functional network connectivity during abstract and concrete word imagery.

Purpose of the Study:

• To compare condition-specific functional network connectivity during the imagery of abstract and concrete words.
• To determine if abstract and concrete concepts exhibit different functional network connectivity patterns.
• To explore the neural basis of the observed differences in processing efficiency.

Main Methods:

• Group Independent Component Analysis (ICA) was used to obtain functional networks.
• Condition-specific connectivity was analyzed during abstract and concrete word imagery.
• Functional Network Connectivity Distributions (FNCD) and Wilcoxon rank-sum tests were employed for validation.

Main Results:

• Significant differences in functional network connectivity were found between abstract and concrete word imagery across three network pairs (FDR corrected, p<0.05).
• Concrete imagery exhibited significantly higher functional network connectivity than abstract imagery.
• FNCD analysis confirmed distinct connectivity patterns for abstract and concrete word processing, with higher mean connectivity for concrete words.

Conclusions:

• Abstract and concrete concepts are represented by different functional network connectivity patterns.
• Higher connectivity during concrete imagery, involving linguistic and visual regions with right hemisphere engagement, aligns with Dual Coding Theory.
• The brain demonstrates more integrated and synchronized activity during concrete imagery, potentially explaining faster processing of concrete words.